One swing can change everything. It can reshape an inning or alter the complexion of a season. The Rockies want to view Wednesday’s walkoff home run by Jason Giambi as a defining moment that spells the end of moral victories.

Colorado has no quit. The offense creates gasps and crooked stats that make for wonderful water-cooler conversation. But they need Giambi’s at-bat to have a deeper meaning, to signal that the team is ready to be more of a contender than a carnival ride.

“(Last season), the offense would have quit, gone into shutdown mode once we lost the lead. Not now,” Giambi said after the dramatic 8-5 win over the Dodgers at Coors Field. “We have been playing better defense. We are hitting. If the starters can get us deeper into games, this can be the kind of win that really propels us.”

The Rockies can talk all they want about how it’s too early to judge the season. But had they lost another series after taking an eighth-inning lead against reigning National League Cy Young Award winner Clayton Kershaw, there’s no way they would have avoided a crisis of faith.

How many times can a team get close without questioning its identity? How would they not lament intentionally walking Matt Kemp — Kemp, not Barry Bonds — as the tying run in the ninth?

There’s nothing subtle about Giambi, from his tattoos to his biceps to a mustache that he can seemingly grow between innings. He brings swagger into the batter’s box. He clubbed 13 home runs last season in a part-time role, and the Rockies exercised his $1 million option this season to get roughly 30 games at first base in between pinch-hit at-bats.

Last season, Giambi excelled as a starter (12 home runs) but struggled off the bench. He entered the ninth inning at-bat against left-hander Scott Elbert fresh off a strikeout the previous game in a similar situation.

That failure fueled Wednesday’s success. A student of hitting, Giambi knew something was wrong with his swing when he was unable to catch up to Kenley Jansen’s 93-mph fastball. Seeking a fresh set of eyes, he asked hitting instructor Carney Lansford for help. Lansford compared frames of Giambi’s three-home run game in Philadelphia last season to his Tuesday at-bat.

“I thought he might be crouching too much. But the only difference was a slight leak with his front hip,” Lansford said. “He knows his swing so well he went right to the cage and fixed it.”

With no outs, Giambi stepped in with Eric Young Jr. at third and Marco Scutaro on second. These are the types of moments that pushed Giambi to lose 10 pounds and work out relentlessly with Troy Tulowitzki and a crew of young players in Las Vegas all winter.

“It’s why you come back. And this was a perfect spot,” Giambi said. “Sure, they could walk me, but CarGo (Carlos Gonzalez) is so hot and he’s on deck.”

The Dodgers brought in a fifth infielder, moving Andre Ethier to first.

“They needed an extra outfielder,” quipped manager Jim Tracy.

Tracy could laugh because a micromanaging decision was camouflaged. He insisted he had no regrets about intentionally walking Kemp, even after Kemp scored from first to tie the game on Dee Gordon’s double.

“That’s on me, and I’d do it again,” Tracy said.

Giambi deposited a fastball over the center-field fence, flooding home plate with Rockies players. Rex Brothers’ failure was a footnote, Kemp’s race around the bases an afterthought.

One swing can change everything.

“There’s not a drug you can take. You can’t buy this feeling,” Giambi said. “It’s like the scene in ‘The Natural’ when he shatters the lights. Nothing compares. Now, we need to turn it into something.”

Troy is a former Denver Broncos and Colorado Rockies beat writer for The Denver Post. He joined the news organization in 2002 as the Rockies' beat writer and became a Broncos beat writer in 2014 before assuming the lead role ahead of the 2015 season. He left The Post in 2015.

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